Mass spectrometry is a powerful technique used for chemical analysis, for example, for determining the chemical composition of a sample. One method of performing a mass spectrometric analysis includes the use of an ion trap, which dynamically traps ions from a sample using a time-varying electric field generated by electrodes that receive a time-varying signal, such as a radio frequency (RF) signal, from an electrical signal generation source. By gradually changing the characteristics of the time-varying signal, such as the signal's amplitude or frequency, the ions may be selectively ejected from the trap. This occurs because ions with certain mass/charge ratios will be ejected when the time-varying signal has certain amplitude and/or frequency characteristics.
Mass spectrometers may be very sensitive and may require regular tuning or calibration to maintain accuracy and sensitivity. For example, if a mass spectrometer is set to a detection range of 2,000 Daltons (Da) at a maximum RF voltage of 2 KV, then a 1/2,000 drift (0.05%) in the RF voltage would result in a 1 Da error in the measurement result. Such an error could lead to an identification of a wrong isotope or even a wrong compound. This would obviously be unacceptable. Therefore, for example, if an acceptable error is 0.1 Da, the drift in the RF voltage needs to be kept within 0.005%.
Therefore, there is a need for a mass spectrometer having an improved accuracy.